Fuel pump



H. CAMINEZ Nave 5, 1929.

FUEL PUMP Filed Oct. 1, 1928 2 Sheets-Sheet l a-wvewtoz H. GAMINEZ Nov, 5, 1929.

FUEL PUMP Filed Oct, 1, 1928 2 Sheets-Sheet 2 Patented Nov. 5, 1929 treads P T if NT @FFEQZE HAROLD CAMINEZ, OF GARDEN CITY, NEN YORK, ASSIGNOR TO FAIRCHILD-CAMINEZ ENGINE CORPORATION, OF NEW YORK, N. 'Y., A CORPORATION OF NEW YORK FUEL PUMP Application filed October 1, 1928. Serial No. 309,442.

This invention relates to internal combustion engines and has for its general object to provide a new and improved fuel'fwding means for such en ines.

One of the speci 0 objects of this invention is to provide a new and novel type of reciprocating fuel feed pump in which the quantity of fuel that is pumped will be determined by the number of pump'strokes, so that a counter operated by the pump will give an exact record of the quantity of fuel consumed by the engine.

At the present time it is usual to incorporate in the fuel line a flow meter to determine the amount of fuel consumed by internal combustion engines used on airplanes and automobiles. The 'usual flow meter is a complicated and sensitive apparatus which is easily put out-of order. By using a fuel pump such as described in this invention, which will deliver a measured quantity of fuel only as fuel is used, a record of the quantity of fuel consumed by the engine is easily f obtained by a counter or similar device at-- tached to the fuel pump and recordlng the number of pump strokes. In this way the usual fuel flow meter may be dispensed with and a more accurate check on the fuel consumption of the engine obtained.

Another object is to provide a positively operating fuel feeding means which main- 1 tains a constant pressure at all times and does away with the necessity of using a vacuum tank.

Still another object of this invention is to provide a reciprocating fuel feeding pump which is simple in construction, positive m operaton and has few working parts.

The principal object of this invention is to provide an improved fuel feeding 'fpunip -"l which has none of the objectionable features.

ust mentioned and is simple in construction and reliable in operation.

Other objects and advantages ofthe ent invention will become apparent from the following description, claims and appended drawings, in which:--

Fig. 1 is a view in perspective showing the shaft and pinion for raising the plungers of the improved fuel feeding mechanism and section showing the construction and arrangement of the cylinders and plungers.

Fig. 3 is a vertical transverse view in section of one of the cylinders and its associated plunger showing the plunger being raised by means of the continuously rotating operating shaft.

Fig. 4: is a horizontal transverse view in section taken on the line M of Fig. 2 and showing the means for automatically controlling the operation of the plungers.

Fig. 5 is a developed view of the cylindrical surface of the right plunger showing the rack for raising the plunger, the alignmg grooves for the plunger, and the cam groove for efiecting the rotary movement of the plunger at the extremeupper and lower limits of travel of the plunger,

Fig. 6 is a perspective view of the means whereby one cylinder controls the reciproca-' tory movements of the other cylinder.

Fig. 7 is a view in section showing a modified construction for the piston, v

Fig. 8 is a view in section showin another modification in the construction of t e piston.

The numeral 1, Figs. 1 to 4i re resents a cylinder block bored with two vertical c linders which are closed at their upper en 5 by means of a cylinder head 2 attached to the cylinder block by means of suitable screw studs. Within each of the cylinders is a holloW'cylindrical plunger 3 which is adapted to reci rocate vertically. Each plunger 3 is norm a y urged downward by means of a spring 4 interposed between the cylinder head fiend the plunger 3.

Rt 8 best illustrated in Fi s. 2 and 3, each of the cylinders is rovide with a suitable piston consisting o a disc 5 which is fur nished with a stem, having a threaded portion adjacent'to the disc, an upper smooth cylindrical portion above the same and terminating in a threaded stud. There is a shoulder 8 at the junction of the smooth portion with the threaded stud. A disc 6 is screwed on the lower threaded portion of the stem and interposed between the discs 5 and as a motor or wind wheel.

6 is a suitable disc or washer 7 composed of rubber or other suitable resilient material, such as leather, the packing disc or washer 7 being formed substantially cup-shaped and fitted snugly within the cylinder so as to form a liquid-tight packing for the piston. The smooth cylindrical portion of the stem projects through a hold in the lower end of the plunger 3, while the threaded stud is provided with a suitable nut and washer which are screwed tightl against the shoulder 8 thus preventing t e piston from becoming detached from the plunger 3 and at the same time allowing the plunger 3 to turn freely with respect to the piston.

The plungers 3 and their associated pistons are adapted to reciprocate vertically under the combined action of the springs 4 and mechanism now to be described and perform the usual functions of a pump plunger, drawing liquid fuel into the cylinder on the up stroke and forcing it out again under pressure on the. down stroke. The various valve connections incidental to a plunger pump form no part of the present invention and need not be described herein nor be shown in the drawings.

Extending lengthwise of each plunger 3 is a rack 9 which is adapted to mesh at certain times with a gear pinion 10 carried by a constantly revolving shaft 11 driven in the direction of the arrow, Fig. 1, by the internal combustion engine to which the fuel feeding mechanism may be attached or by any other suitable and convenient source of power such The shaft 11 is supported by means of suitable bearings 12 mounted on the side of the cylinder block as shown in Fig. 1. A suitable dust cover 13 is provided for enclosing the gear pinions 10, the shaft 11, and part of the control mechanism which will be described hereinafter.

Mounted upon the side of each plunger 3, Fig. 5, is a pair of aligning grooves 14 and 15, either of which may be engaged by an antifriction roll 16 carried by a stub-shaft 17 mounted upon a plate 18. The plate 18 is carried by the cylinder wall and covers an opening through which the anti-friction roll stub-shaft 17 projects, the object of this construction being to provide for the easy removal and replacement of the rolls 16. By reference to Fig. 5 it will be noted that the aligning grooves 14 and 15 are joined together at their upper and lower ends by means of openings 19 and 20 in the wall separating the two grooves. The antl-friction roll 16 associated with each plunger normally projects into one or the other of the grooves 14 and 15, depending on whether the plunger i moving downward or upward, and serves to prevent the plunger from turning on its axis except at such times as the plunger may be at its extreme lower or upper limits of travel.

The anti-friction roll 16 is adapted to traverse the groove 14 as the plunger moves downward and to traverse the groove 15 as the plunger moves upward. When each plunger reaches its extreme lower limit of travel, the plunger will be turned on its axis until the anti-friction roll 16 is at the lower end of the groove 15. When the plunger roller 16, the rack 9 is carried out of engagement with the pinion 10.

For the purpose of turning the plungers as they arrive at their extreme upper and lower limitsof travel, the following mechanism is provided:

Each of the plungers 3 carries a spirally or singularly) arranged cam groove 21 whic is engaged y an anti-friction roll 22. The anti-friction roll 22 is carried by means of a short stub-shaft upon the lower end of a leaf spring 23 which projects downwardly along the side of the cylinder and is fastened to the side of the cylinder block by means of screws24. Suitable dust covers 25 serve to enclose the springs 23 and protect the springs from injury. The anti-friction roll 22 is constantly in engagement with the cam groove 21- and traverses the groove as the plunger moves upward or downward. The cam groove 21 is so disposed upon the surface of the plunger that the leaf springs 23 are tensioned in one direction or the other as the plunger moves upward or downward so that when each plunger reaches its extreme upper or lower limit of travel the spring tends to turn the plunger on its axis to bring the desired groove 14 or 15 into position so that the anti-friction roll 16 can enter the same.

For instance, as the left cylinder plunger 3, Figs. 2 and 4, is urged downwardly under the impulse of the spring 4 the end of the leaf spring 23 associated with the left plunger will be gradually urged to the left due to the camming action of the groove 21 so that when the plunger is near the end of its downward stroke the spring 23 will be almost fully deflected and will have a tendency to turn the plunger clockwise upon its axis as viewed in Fig. 4, such movement being prevented, of course, by reason of the presence of the anti-friction roll 16 in the aligning groove 14. When the plunger reaches the end of its downward stroke, the opening 19 in the wall separating the two aligning grooves 14 and 4F so as to be diametrically opposite each other v 15 associated with the left plunger 3 will be brought into juxtaposition with the antifriction roll 16 so that the plunger will now be free to turn on its axis in a clockwise d1- 5 rection under the impulse provided by the tension leaf spring 23. The turnlng movement of the plunger 3 just described causes the rack 9 carried by the left plunger 3 to mesh with the continuously revolvlng gear 10 pinion 10 carried by the shaft 11 with the re-. sult that the plunger 3 will now be carried upward compressing the spring 4 and causing the anti-friction roll 16 to enter the groove and prevent any further turning of 15 the plunger on its axis.

the leaf s rin 23 to be tensioned as the 20 P g plunger 3 moves upward so as to tend to turn the plunger back to a position ready for descent. For instance, as the left plunger 3 travels upward, the lead spring 23 associ- 25 ated with the left plunger will be urged to the right, Fig. 4, so as to have a tendency to turn the plunger 3 in a counter-clockwise direction, such movement being prevented by the presence of the anti-friction roll 16 in the aligning groove 15. When theplunger 3 reaches its upper limit of travel the opening 20 is brought into juxtaposition with the antifriction roll 16 with the result that the;

plunger 3 will now be free to turn in a counter-clockwise direction until the anti-friction roll 16 is at the upper end of the aligning groove 14.

The plungers 3 are alike in most respects, each being provided with a rack 9, a pair of aligning grooves 14, 15 anda cam groove 21 all of which are intended to function as has just been described; however, it will be observed by reference to Fig. 4 that the plates 18 supporting the anti-friction rolls 16 are located on the outside of the cylinder block with respect to the vertical axis of the cyl inder block. Consequently the aligning grooves 14 and 15 carried by the rlght plunger 3 occupy positions just the reverse of the positions occupied by the grooves 14 and 15 carried by the left plunger. Furthermore, the cam groove 21 associated with the right plunger 3 is so constructed that its cont; figuration is that of an inverted letter S; in

other words adevelopment of the surface of the left plunger 3 placed beside the development of the right plunger 3, illustrated in Fig. 5, would be just the reverse of the development in this figure. Both of the plungers are intended to' function alike in their upward and downward movements in so far as the cycle of events is involved, the only difference being that the right plunger 3 will be turned counter-clockwise when it reaches its lower limit of travel and clockwise when it reaches its upper limit of travel, whereas the left plunger 3 is turned in just the o posite direction as it arrives at its lower an upper limits of travel respectively.

In order to control the reciprocatory movements of the plungers 3 and ensure a proper sequence of events in their operation, means is rovided which consists of a member 26 sli ably mounted in a recess in the cylinder block 2.

The member 26 has the general shape shown in Fig. 6 and is guided in its sliding movements by means of slots 27 thru which pass studs 28 carried by a rib-like bearing surface 29 integral with the cylinder block 2. The member 26 is of suflicient length to extend in front of both of the racks 9 and is provided with notches 30 and 31 which are adapted to cooperate at times with the racks 9 of the right and left plungers respectively.

The notches 30 and 31 are just large enou h for the racks 9 to move freely between t e walls of the notches and are so disposed in the member 26 that either one or the other,of the racks is in engagement with one of the notches 30 and 31, it being understood, of course, that the notches 30 and"'31 are of sufficient depth to revent interference with the teeth of the rac s. Each of the outside corners of the notches 30, 31 is formed with a slightly rounded projection as at 32, Fig. 6, in order to prevent the corner from cutting into the side of the racks 9 as the plun ers 3 are turned under the impulse of the lea springs 23 and also to prevent any binding action which might occur if. the notches were simply squared off. Furthermore, the slight projection 32 makes it possible to secure a better fit and serves to reduce lost motion between the rack 9 which may be in engagement with its associated notch and the notch itself.

In order to more fully understand the manner in which the member 26 controls the reciprocatory movements of the plungers 3 a brief description of the operation of the plungers will now be made.

Assuming that one of the plungers 3, the right one, Figs. 2 and 4, for instance, is in its extreme upper position, the aligning groove 14 associated with the right plunger 3 will be exactly above the anti-friction roll 16 associated with the right plunger and the leaf spring 23 associated with the plunger will be tensioned just enough to hold the plunger so that it is ready for descent. When the plunger is in this position, it is held from descending by virtue of the lower end of the rack 9 resting upon the left edge of the right notch 30 in the member 26.

In order to permit the right plunger to descend, it is necessary that the member 26 be shifted to the left, Fig. 4 so as to remove the corner upon which the right rack 9 rests from beneath the end of the latter. It will be observed by referring to Figs. 2 and 4 that the left plunger is in the act of descending under the reaction of its spring 4. It will also be noted that the rack 9, associated with the left plunger 3, is embraced by the notch 31 in the left end of the member 26 so that the member 26 is incapable of movement in either direction. While the left plunger is descending, its anti-friction roll 16 will transverse the alining groove 14 until the plunger reaches its lower limit of travel. As the plunger descends, the cam groove 21 carried by the left plunger will gradually tension the leaf spring 23 so that when the plunger reaches the opening 19 separating the two grooves 14 and 15, the spring 23 will be released and the plunger will be turned clockwise on its axis as shown in Fig. 4, until the antifriction roll 16 is at the upper end of the 29 groove 15. At the same time the rack 9 carried by the left plunger 3 will be brought into mesh with the constantly rotating pinion with the result that the pinion will raise the plunger until its reaches its upper limit of 25 travel. The shifting of the plunger in a clockwise direction also causes the member 26 to move to the left, Fig. 4, until the corner which serves to hold the right plunger 3 in its vertical position is removed from under 30 the end of the rack 9, thus permitting the plunger to descend under the impulse of its spring 4. and permitting the lower end of the rack 9 to pass between the walls of the notch 30 as it descends. Meanwhile, as the right plunger 3 descends, the left plunger 3 will be raised by the pinion 10 until it reaches its extreme upper limit of travel, the anti-friction roll 16 traversing the aligning groove 15 and the cam groove 21 acting to tension the leaf spring 23 in the op osite direction to the tension applied as t e plunger moves downwardly.

When the left plunger nears its extreme upper limit of travel the leaf spring 23 will have a tendency to turn the plunger in a counter-clockwise direction with the result th at, when th 2 opening 20 joining the aligning grooves 14 and 15 arrives opposite the antifriction roll 16, the plunger will be turned on its axis in a counter-clockwise direction until the anti-friction roll 16 is at the lower end of the aligning groove 14 carried by the left plunger. As the left plunger is turned on its axis the rack- 9 will be carried out of mesh with the pinion 10 and, at the same time, the lower end of the rack will be carried over the right corner of the left notch 30 in the member 26. Since the right plunger 3 is still descendin at this time, the member 26 is incapable o movement until the right plunger 3 has rc ched its extreme lower limit of travel with the result that the left plungerwill be locked until the member 26 is shifted by means of the turning of the right plunger on its axis. The left plunger remains locked until the right plunger completes its downgo thru the same cycle of events as before. While the fuel su ply mechanism just described has been 5 own in the drawings as,

being provided with two cylinders, it is to be clearly understood that any number may be used as desired, and, if necessar the fuel feeding mechanism may be provi ed with a single cylinder, in which case the member 26 may be dispensed with.

In Figs. 7 and 8 are shown modifications in the construction of the piston. The numeral 33 represents a disc which is provided with a threaded portion 34 passing through a hole in a cup-shaped disc or washer 35 similar in all respects to the washer 7. The threaded ortion 34 also passes through a hole in a isc 38, an aperture in the plunger 3, and through a washer 39. Suitable nuts serve to clamp the disc 33, cup-shaped washer 35, disc 38. and plunger 3 firmly together so that the plunger is prevented from turning with respect to the piston.

In Fig. 8 the construction shown is identical tothe construction shown in Fig. 3 except for a slight change in the threaded portion of the disc 5. As shown in Fig. 8 the threaded portion of the disc 5 has formed integral Wilda,

fore, to limit myself to the specific construction shown an described, but to interpret the invention broadly within the scope of the appended claims. I

What I claim as my invention is: 1. In a fuel feeding system for internal combustion en ines, a fuel pump having a working cylin er, a workin piston in said cylinder, a hollow control p unger pivotally connected to said piston, a rack on said plunger, a-continuously rotating pinion, a spring within said plunger for moving said plunger and piston axially of said cylinder to pump fuel, spring means associated with said plunger and. tensioned by the movement thereof in pumping fuel to rotate said plunger to bring said-rack into engagement with said pinion to return said piston, and means for preventing rotation of said plunger except at the ends of its stroke.

2. In a fuel feeding system, a fuel feeding pump having two working cylinders and a piston within each cylinder for pumping fuel, separate spring means, one for each cylinder for operatlng the piston therein to pump fuel and interlocking means for restraining pump- 

